Re: [PATCH net] cfg80211: fix callback type mismatches in wext-compat

[Sami Tolvanen]

On Tue, Nov 17, 2020 at 1:45 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> On Tue, Nov 17, 2020 at 12:59:02PM -0800, Sami Tolvanen wrote:
> > Instead of casting callback functions to type iw_handler, which trips
> > indirect call checking with Clang's Control-Flow Integrity (CFI), add
> > stub functions with the correct function type for the callbacks.
>
> Oh, wow. iw_handler with union iwreq_data look like really nasty hacks.
> Aren't those just totally bypassing type checking? Where do the
> callbacks actually happen? I couldn't find them...

The callbacks to these happen in ioctl_standard_call in wext-core.c.

Sami